This project proposes to examine the association between heat exposure and traumatic injury risk in agricultural workers, assess a potential mechanism for increased injury risk in crop workers exposed to heat stress and its relation to productivity, and examine the feasibility of using a biomarker of heat acclimation to detect workers at risk for heat-related illness (HRI) and injury, with the ultimate goal of prevention. Th career development plan and research outlined in this proposal will allow Dr. Spector to build upon her background in epidemiology, biostatistics, and occupational health; combine her interests in occupational injury and HRI prevention; and develop new skills in 1) effectively using workers' compensation data to explore hypotheses; 2) testing hypotheses in working populations; and 3) translating research into practice. The local environment for public health research in Washington is outstanding, and Dr. Spector's proposed mentorship committee includes accomplished mentors with established, multidisciplinary research programs. Under the primary mentorship of Dr. Fenske, Director of the Pacific Northwest Agricultural Safety and Health (PNASH) Center, Dr. Spector will: 1) estimate the association between heat exposure and injury risk in agricultural workers using established climate models and WA workers' compensation data; 2) estimate associations between heat stress, psychomotor performance, and productivity in adult outdoor crop workers in field harvest conditions; 3) assess the feasibility of using urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker of heat acclimation in field conditions; 4) and address NIOSH's r2p mission through dissemination of findings to the agricultural community and industry. We expect, based on previous work, that heat stress is associated with increased injury risk and decreased psychomotor performance and productivity, particularly in poorly acclimated workers, and that increases in heat strain are associated with increases in 8-OHdG. The results, protocols, and dissemination products developed during the course of this project will be valuable outputs that we expect will improve our ability to estimate future productivity losses and health effects related to climate change, wil help us to engage employers in HRI prevention efforts, and will enable us to better measure the effectiveness of HRI prevention interventions. The ultimate goal of this work is to reduce traumatic injuries and improve the health and well-being of agricultural workers (NORA AFF Strategic Goals 4 & 5) in a changing climate. This harmonizes with Dr. Spector's ultimate career goal of preventing occupational injuries and illnesses and their consequences in at-risk occupational populations.